Tension adjusting means for chain saws or the like



c. VAN AUsDALL July 14, 1953 TENSION'ADJUHNG uEANs FOR CHAIN sAw 0R THE LIKE Filed .June 16, 1949' 2 Sheets-Sheet l Wig. 3. Carl Van usdall INVENTOR.

July 14, 1953 c. VAN AusDALL 2,645,254

. TENSION ADJUsTINc MEANS FOR CHAIN sAws oR THE LIKE Filed June 1e, 1949 f2 sheets-sheet 2 i Carl Van/Jusdal/ IN V EN TOR.

Patented July 14, 1953 OFFICE .f i Y ,x' TENSION ADJUSTING MEANS FOR CHAIN SAWS R THE LIKE f 13 Claims. f 1

The present invention relates to a tension adations in which a flexible member of loop formation requires tightening or loosening relative to Vits supporting means. By way Of example, the invention Vmay be applied to the cutter element of a chain saw which is usuallyin the form of a chain or similar carrierl for Saw teeth, connected at its opposite ends to form a loop, and supported for movement upon sprockets, or by means of a driving sprocket and a track. Proper tensioning in such a case is conducive of effective operation of the sawyand usually a release of tension is necessary in removing and replacing the chain.

One object of the invention is to provide an improved form of tension adjuster which is rapid and positive in action, both to tighten and loosen an endless cutter or the like.

Another object is to provide a tension adjuster so constructed as to require a minimum of servicing or care, and which is composed of simple and inexpensive parts that cannot be lost or misplaced in the course of cutter replacements or repairs.

Another obj ect is to enhance the durability and serviceability or a tension adjuster, without the employment of parts subject to loosening in the presence of `vibration or hard usage.

A further object is to provide a novel cutter driving unit for applicationtoa garden tractor, with tension adjusting means incorporated therein in such manner as to adjustably supporta chain saw in alternative positions, for tree felling or for cutting-off operations.

Another object is to p-rovide a unit of the character statedY which is simple, inexpensive, and highly efcient as a driver and as an adjuster for endless cutters operating in conjunction with wheeled implements.

The foregoing and other objects `are attained by the means described herein and illustrated. upon the accompanying drawings, in which:

Fig. 1 is an elevational view showing the device of the invention mounted upon the frame of a garden tractor, with a chain saw disposed in substantially horizontal position for tree felling.

Fig; is .an enlarged view of a ratchet wheel g,

carl van Ausaau, Liberty, nia.

`Application June 16, 1949, Serial No..99,417

and gear assembly which forms a. detail of the tension adjuster.

Fig. 6 is a view similarto Fig. 2, showing a` modied-form of cutter support.

, As was pointed out previously herein, the de` ally `a power transmission unit including suitable i gearing to be driven by a pulley 9 belted to a garden tractor motor or other source of power. Such a motor is shown at Id, Fig, V3, including a pulley I2 that may drive the transmission unit pulley 9 by means of a belt, not shown. When the transmission unit k8 is applied to `thetractor :ir-ame, as by mounting the unit upon the parallel mounting rods I3, the pulleys I2 and 9 vwill be in coplanar relation to receive a driving belt. 'I'he `mounting rod connection is shown at I3 in each of Figs. l, 3 and 4. I l. v

At this point in the description, it may `be noted that the garden tractor of Fig. 3 consists of a frame I4 supporting the single Wheel I5, the latter being driven through gearing in the frame actuated by the belt and pulley I6. The pulleys IG and I2 may be `xed on the shaft of `motor I0, or if desired, the drive between the shaft and the pulleys may be effected through a centrifugal clutch or the like il, carried by the motor shaft. The tractor may be guided by means of handles in the usual manner, and the handles may carry a throttle and a lever for declutching the wheel I5 at a location within the connes'of the frame.

At the rear of the tractor frame is a hitch bar I8, whileat the forward end the frame carries an extending motor mounting plate or member I9.

Plate i9 hassidese-ZO recessed transversely as at ZI to-accommodate the pair of mounting rods I3. -The rods may be secured in the recessesin anysuitable manner, as by means of bolts 22 which pass through transverse holes drilled in vthe rods.

The rods` I3 extend from one side of the motor mounting plate, as shown in Fig. 1, and upon these extending-ends `the power trans,

, mission unit is adapted to be supported and locked, as by4 means of set screws 23. The unit B may be shifted` along the rods I3 before tightening theset screws, to obtain a proper driving 3 v tension of the belt to be applied for driving the pulley 9 from the motor pulley l2.

The characters 24 and 25 indicate, respectively, a fuel tank and a cooling air hood for the motor. Openings 26 in the motor mounting plate may be utilized for the mounting of various 1mplements upon the tractor.

Referring now to Fig. 4, it will be understood that the power transmission unit 8 is a metal casting or casing providing a head 21 having a lateral extension 28, a neck 29 at right angles to extension 28, a lower body portion 39, and a lateral extension 3l integral therewith.Y Bee tween the neck 29 and the body portion 30, the casing is provided with bosses 32 drilled in substantial parallelismwith the body extension 3l 4 of any suitable length, and its thickness will of course be "-less than the overall Width'of the chain as measured transversely across the saw teeth. This is common practice in the chain saw art, and should require no detailed explanation, At the anchorage end 41, the blade may be perforated as at 49 to accommodate studs,

`member comprises @casting or block I of subl stantial thickness and rigidity, in Which are emto receive theextending endsV of the mounting rods I3. As stated before, a set screw 23 in each bossserves as means to securely fix the unit to the mounting rods. Y

`Within the head 2l is aV pair of bevel gears 35-36, or gears of any other suitable type, meshing to transmit motion of the pulley shaft 33 to the ,main shaft 34 of the unit. Shafts 33 and 34 are journaled in anti-friction bearingsof any approved type. Within the body 39, a bevel gear 3'! fixed to the main shaft, meshes with a similar gear 33 to drive a sprocket shaft 39 journaled in the body extension 3|. This shaft and extension project laterally in a common Vdirection, at right angles to both of the shafts 33 and 34. Fixed to the end of shaft 39 is a driving sprocket 49 designed to accommodate a chain or similar flexible endless carrier 42 for the saw teeth 4I (Fig. 2). As will be understood, saw teeth are applied to the carrier or chain along the full length of the latter, in accordance with common practice. The chain or carrier, where unsupported by the sprocket, rides in the peripheral groove 43 of a normally Vstationary blade 44 carried by the housing or case 8. Details of this'will be described in due course.

It will be noted that when the unit is applied to the tractor, as in Fig. 1, the sprocket 49 is in a substantially vertical plane. A second sprocket 45, however, is disposed in a substantially horizontal plane, and may be driven byreason of its fixation to the lower end of main shaft 34. This second sprocket is adapted to accommodate and drive the same chain or carrier 42 above mentioned, when the blade is disposed in the operative position of Fig. 1. As will be explained later, the blade is adapted for rapid attachment Lto the unit housing in alternative positions, for :felling and for cutting-off operations. .forming these operations, the workman' guides In perthe cutter by manipulating the pair of handles 46 of the tractor to which the unit is applied. Thus, in performing a cutting-off operation, the

handles of the tractor will be manipulated in an, vupright plane, whereas in felling, the handles will be moved laterally to swing the tractor siderigid plate, or a series of laminations, so con-` structedas to provide a butt or anchorage end 41, and a forward curved end 48, with a groove S43 extending continuously from one edge of the butt, around the curved end, and back tothe butt, as shown upon Fig. 2. The blade may be bedded and secured the inner ends of the studs or bolts,` 5a The block may include integral spaced bosses or ears 52 furnished With Dal"- 'allel bores to tightly aOInmOdate the inner ends 53 of a pair of rods dr -balS 54 and 55 that extend in a direction opposite tothe direction of extension of the blade. The IOdS 01' bars may be secured in the bores of the "ears 52 by means of pins'55, or otherwise.

The blade butt 41V may be provided with a greater number of perforations 49 than the number 'of studs 50 carried by the block, in order to permit a greater than normal extension of the blade end 48 from the block, in the event of undue stretching or wearing of the chain. TheY number and character of the means permitting such extension of the blade relative to the support block 5|, is of course subject to variation and choice of the designer.

v The rods or bars 54 and 55 are parallel, and the major axisY of the blade 44 may or may not be parallel thereto, but nearly so, if desired. Round stock is preferred for the members 54 and 55, although it may be quite possible to make them of angular or part-round stock, if desired. One of the rods is to be milled or otherwise slotted transversely as indicated at 51, to form a rack engageable with a rotary pinion for extending and withdrawing the blade relative to the unit housing. Such a pinion is indicated at 53 upon Figs. 1 and 4. It may be noted that the pinion teeth extend partly into one of the parallelbores 59 which slidably receive the rods 54 and 55. These bores 59 preferably are drilled in an end cap @il which closes the lower end of unit body part 39. The end cap may also carry the lower bearing (not shown) for the main shaft 34.

Referring to FigsA and 5, it will be seen that pinion 58 is on a shaft with a ratchet wheel 6I, both the pinion andthe wheel being fixed One end S2 of the shaft is squared or otherwise formed to receive a tool, whereby the pinion may be rotated to reciprocate the rack rod 54 and the saw blade attached thereto. VThe opposite end ,63 of the rack actuator shaft is preferably round,

and Yserves as a bearing area to support the shaft within'the body 3D.V A second bearing area for the` shaft is shown V'at 54, and this bearing area Mis* `iournaled in a plate secured to the side of theY housing body. Thev plate may be rigidly mounted on the body by means of screws or pins 61. l Y

Referring to Fig. 1, it should readily be understood that any continuous chain or the like resting in the blade groove 43 and embracing the sprocket 45, may be tightened or tensioned by rotating the pinionfshaft head 62 in counter- `clockwise direction. By rotating the shaft head in the oppositeidirection, the chain may be relieved of tension, even to the' extent of permitting its removal bodily from the sprocket and the chain groove.` After removal of thelfchain, the pinion shaft may be rotated countferclokwise sufficiently to eject the rods 54 arid -55 from their guide bores 59, thereby enablin the operator to completely detach thebladejassembly of Fig. 2 from the unit. Y

Normally, rotation of the clockwise or tension-relieving direction, is opposed by a pawl 69 engaging the `teeth of ratchetwheel 6i (Fig. l). Tlffie pawlmay pivot at B1, `and its engaging end' may be yieldingly urged against the ratchet wheel teeth by means of any suitable type of sprjing lor yielding means,

`here shown at 10 as a coiled compression spring. i

By means rof this arrangement, Athe operator may simply. `rotate the 'pinion shaft head in counter'- clockwise direction toftensionfthe saw chain, and when the proper tension point is reached, the rpawl `Silholds thejpinionlrshaft against reverse rotation. Thusyfthe tension adjustment is accomplished easily and `quickly with no further effort, `and without tightening any supplemental -clamps or bolts subsequently to adjustment.

" When the operator wishes to rotate the pinion `shows the blade disposed horizontally for felling "a'standing tree, for example. Subsequently to Vthe felling operation, the user of the device may wish to saw the tree into short lengths. This will require a vertical disposition ofthe blade 44. Ac-V cordingly, the lateral extension 3i (Fig. l) of the unithousing is provided with an end cap 60 similar toV that at 60, and carrying the same cone stituent elements as were just described with respect to the tension adjustment. The end cap 60 has its .rod-receiving bores 59 disposed in a Y vertical or upright plane, so that by .inserting therein the rods of the Fig. `2 blade assembly, the

blade will repose in a plane which includes `a` diameter of sprocket 40. Thus, the blade 44 will be disposed in a vertical plane, which is proper for cutting-off operations.

The end cap 6.0 and body extension 3l carry the same arrangement of pinion, pawl, and ratchet wheel assembly as was previously explained herein, wherefore it is believed superiiuous to repeat the description of such parts. Accordingly, the parts which are identical have been denoted by primed reference characters corresponding to .the partspreviously described.

Thus, the pawl 69 is'identical to pawl 69, pinion 58' is identical to pinion 58, ratchet wheel 6i' is identical to wheel 6 I, etc. When the blade assembly vof Fig. `2 is mounted by means of the bones59 of4 cap 60', the tension adjustment and all other manipulations .are as previously set forth.

f From the foregoing, it is apparent that the blade assemblymay `be disposed in alternative operating positions, with no appreciable expendij ture of time and effect. The power transmission "unit Biremains fixed to the tractor, and it is not necessary to disturb the driving connection betweenthe motor pulley l2 and the unit pulley 9.

the `pinibii shaftftz in All operating parts subject to Wear are encased and run in lubricant, so that troublesomelreplacement of parts has been largely eliminated. The illustration, Fig. 6, suggests a modied form of blade assembly that might be substituted for the assembly shown in Fig. 2. In themodied structure, a shock absorbing feature is incorporated, to dampen shocks transmitted as the saw chain encounters hard spots or any obstructions blade 44, including `fastening means 50.

vsupport 5I is distinguishable from support 50,

in the material operated upon. The` character 44' in this instance indicates a blade similar to The in that the ears 52 are' provided with bores 53' enlarged sufficiently to permit sliding movement of the rods 54 and `55 therein. Movement of the rods `in one direction is limited by pins or stops 'I5 secured to the rod ends, whereas movement in the opposite direction is yieldingly opposed by springs 16 or other yielding means located between each ear 52 and a collar or shoulder 11 iixed` upon each rod intermediate its ends. By means of this arrangement in the blade assembly, any obstruction tending to cramp `or stop the saw chain while in operation, will result in limited momentary slackening of the chain as` permitted Vby the springs, followed by a slight jump or jerk suiiicient to relieve the chain and return it to normal tension. The shock absorbing function of the assembly will tend also to cushion any shocks that might otherwise be transmitted to the tractor, and the operator thereof. i l The device of the present invention constitutes a vast improvement over devices heretoforeprof posed for performing the same or similar Work,

and under exhaustive tests has proven highly effective. All adjustments and interchanges are vquickly made with little eifort, and with one simple tool. There are no detachable or removable small parts to be lost or misplaced in normal use of the device, -and this feature not `only avoids annoyance and delay, but accidents also.

It is to be understood that variousmodiflcations and changes in the structural details of the device may be made, within the scope of the appended claims, without departing from the spirit of the invention. For example, the blade 44 will sometimes be provided with a chain ltrack `other than a groove such as 43, a rib beinga common expedient in the art. Drive pulley `9, of course, might well be asprocket, andthe nature of .the gearing within the case or housing 8 is a matter immaterial to the invention. Moreover, the pawl motor-driven vehicle, comprising in combination,

a housing including an upright main drive shaft rotatablewithin the housing, a laterall extensionV on the housing substantially at right angles thereto,` .a second shaft longitudinally mounted for rotation in said extension and including a driving connection with the main drive shaft, a. secondllateral extensionon the housing including a third shaft at substantial right angles to both theA main drive shaft and the second shaft, said thirdshaft including a driving connection `with one; of the othershafts for rotation therewith, a sprocket,'xed on the `third shaft aforesaid, an elongateflat chain-supporting blade, cooperative means .associated with the blade and the housing, for supporting the blade Ain the `plane of the sprocket, and means for mounting the housing upon a motor driven vehicle, with the motor in driving relation with said second shaft.

.2. -A chainsaw attachment for application to a motor-driven vehicle, comprising in combination, a housing'including Van upright mainY drive shaft rotatable withinl the housing, aV lateral extension on the housing substantially at right` angles thereto, a second shaft longitudinally mounted for rotation in said extension and including a driving connection Awith the main drive shaft, a second lateral' extension on the housing including a third shaft at substantial right angles to both the main drive shaft and the second shaft, said third'shaft including a driving connection with oneof the otherV shafts for rotation there.- with, a sprocket fixed on the third shaft aforesaid, an elongate flat chain-supporting blade, cooperative means associated with the blade and the housing, for supporting the blade in the plane of the sprocket, means for adjusting the blade toward and from the sprocket, and means for mounting the housing upon a motor driven vehicle, with the motor in driving relation with said second shaft.

3. A chain saw attachment for application to 1a motor-driven vehicle, comprising in combination, a portable housing including a pair of bored 4bosses receptive of a pair of parallel bars extending'from the vehicle, means for securing the housing atpreselected locations upon the parallelbars, a saw-chain driving sprocket mounted Vupon the housing in a substantially vertical plane,

meansfor driving the sprocket from the vehicle `motor, anelongate flat chain-supporting blade, and cooperative means associated with the blade the vehicle, meansfor securing the housing at preselected vlocations .upon the parallel bars, a

saw-chain driving sprocket mounted upon the housing in a," substantially horizontal plane, meansfor driving the sprocket from the vehicle motor, an elongate flat chain-supporting blade, and cooperativerack and pinion means associated with the blade and the housing, for support of the blade in the plane of the sprocket, the rack being mounted upon the blade, and the pinion being rotatabltr supported upon the housing for manual actuation for extending and retracting the rack, and latch means normally precluding rotation of the pinion in one direction.

5. A detachable driving unit for an endless band type of cutter, comprising an upright hollow housing bored transversely for slidably receiving a mounting bar, a lateral hollow extension on the housing disposed substantially at right angles thereto, an upright main drive shaft ro- Ytatable' within*the housing, said shaft having an end exposed exteriorly of the lower end of the upright housing, AVa second shaft journaled within the housing extension and disposed substantially at right' angles to the main drive shaft, said second shaft having an end exposed beyond the housing extension-gear means imparting rotafftion :ofthegmain drive shaft to the second shaft,

s a bandcutter support Wheel on the exposed end of the matin shaft, and a band cutter support wheel on the exposed end of the second shaft, a at elonga .ed band cutter support blade having an edge over which the band cutter is trained, and selectibev means'for detachably supporting said blade u .on the housing in the plane of either band cutter sdpport wheel.

6. A detachable driving unit for an endless band type of cutter,"-.:comprising an upright hollow housing includingI means for detachable mounting thereof upon akvehicle, a lateral hollow exhousing imparting rotation of "the mar'ndrive shaft to said second shaft, a band cutter support wheel on the exposed free end of the main drive shaft, and a band cutter vsupport wheel on the ,exposed free end of the second shaft, a flat elongated band cutter support blade having an edge over which the band cutter is trained, selective means uponthe housing adjacent to each cutter support wheel, forrdetachably supporting the blade in the plane of either of said Wheels selectively, and means near each of said wheels to retain the blade at various distances therefrom in the wheel plane.

7. A driving unit for an endless bandtype of cutter, comprising anupright hollow housing including means for mounting same upon a vehicle, an upright main drive shaft journaled for rotatlon within the housing, said shaft-having an end exposed exteriorly'of the lower end of Vthe upright housing, said housing being bored transversely near the lower end thereof to rereceive a blade support bar, a band cutter support wheel on the exposed end of the main drive shaft, and a flat elongatedblade having an edge over which the band cutter is trained,1a bladeV support bar on the blade, receptive in the transversie boresV of the upright hollowhousing, for detachably supporting the blade inthe plane of the band cutter support wheel, a series of teeth on the blade support bar, and means at the transverse bores of the upright housing, to engage certaln of the teeth and Ythereby selectively posi-Y tion the blade supportbar.

8. A driving Vunit for an endless band type of cutter, comprising an upright hollow housing including means for mounting same upon a vehicle an upright main drive shaft journaled for rota: tion within the housing, a Vlateral hollow extension on the housing disposed substantially at right angles thereto, a second shaft journaled within the housing extension and disposed substantially at right angles to themain drive shaft said second shaft having a free end exposed be; yond the housing extension end, said extension end being bore transversely to receive a blade support bar, meansV imparting rotation ofthe ',main drive shaft to said second shaft,'a ,bandI 'transverse bores of the housing extension, for vdetachably supporting the blade in the plane of the band cutter support wheel, a series of teeth on the blade support bar, anfd means to engage the teeth of the blade support bar, including a releasable one-way cluttghing device normally opposing advancement of :the bar through the bores.

9. A driving unit for an endless saw chain,

upright main drive shaft jourrerled @fre-tation within the housing, said sh It having an end exposed exteriorly of the lower end of the upright housing, said housing;V being bored transversely near the lower enjci thereof to receive a blade support bar, a sprqcket on the main drive Shaft at the exposed end thereof, an endless sprocket, With lie blade support bar at the transverse bores of the upright housing, to restrain shifting ofthe blade under the force of tension imposed thereon by drag on the chain in use.

10. A chain-saw construction which comprises in combination, a hollow elongate housing including an axial shaft bearing near one end thereof, a shaft journaled in the bearing and having an end extending beyond the end of the housing, a chain supporting wheel fixed on the shaft end for rotation therewith, the housing end having a pair of spaced parallel openings located at opposite sides of the shaft transversely thereof, a substantially flat bladelike member of oblong conguration having a forward end and a butt, a pair of rod-like extensions on the butt slidably received in the spaced parallel openings of the housing endl, said extensions beingV located upon the blade-like member to position said member in the plane of the wheel aforesaid, an endless saw chain trained over the wheel and the forward end of the bladelike member, a line of rack teeth on one of the rod-like extensions, a rack pinion located interiorly of the housing and including a manually rotatable shaft journaled in the housing at right angles to one of the extension-receiving openings of the housing, with the teeth of the pinion obstructing part of said one opening and engaging the rack teeth of said one extension, a ratchet wheel on the pinion shaft, and a. displaceable pawl on the housing normally opposing rotation of the ratchet wheel and pinion in one direction.

11. A device in accordance with claim 10, in Which the rod-like extension which carries the 10 rack teeth, includes a cushion connection with the butt of the blade-like member.

12. A chain saw construction which comprises in combination, a hollow elongate housing `including a shaft bearing near one end thereof, a shaft journaled in the bearing and having an end extending beyond the end of the housing lengthwise thereof, a chain supporting wheel fixed on the shaft end for rotation therewith, the housing end having a transverse opening therein located to one side of the shaft at right angles to the shaft axis, a second opening in the housing in close proximity to the first` opening and arranged transversely thereof to support a rotary pinion shaft, a substantially fiat blade-like member of oblong configuration having a forward end and a butt, a rod-like extension on the butt slidably received in the first-mentioned opening of the housing end, said extension being located upon the blade-like member to position said member in the plane of the chain supportingwheel, an endless saw chain trained over the wheel and the forward end of the blade-like member, a line of rack teeth on the rod-like extension, a rack pinion located within the limits of the housing and including a manually rotatable shaft journaled in the aforesaid second opening of the housing at right angles to the extension-receiving opening thereof, with the teeth of the pinion obstructing part of the opening last mentioned, and engaging the rack teeth of the extension, means precluding rotation of the extension in the extension-receiving opening, and releasable means normally precluding rotationof the rack pinion in one direction.

18. A device in accordance with claim 12, in which the rod-like extension carrying the rack teeth, includes a cushioned connection with the butt of the blade-like member.

CARL VAN AUSDALL.

References Cited in Vthe file of this patent UNITED STATES PATENTS Number Name Date 463,414 Brown Nov. 17, 1891 1,050,769 Johnson Jan. 14, 1913 1,438,786 Roberts Dec. 12, 1922 2,348,588 Arsneau May 9, 1944 2,357,230 Shade Aug. 29, 1944 2,370,556 Mall Feb. 27, 1945 FOREIGN PATENTS Number Country Date l 118,817 Australia Aug. 14, 1944 

